Gout Flashcards
Gout can be classified into four phases
- Asymptomatic hyperuricaemia
- Acute attacks (characterised by the classic symptoms of gout — pain, swelling and erythema of the affected area)
- Interval gout (the symptom free period between episodes)
- Chronic tophaceous gout (in which tophi develop in the joints that are affected by repeated, acute episodes).
Other risk factors for the development of gout include
● Older age
● Male sex (the risk is also higher for postmenopausal
women than for premenopausal women)
● High alcohol consumption (particularly beer and
spirits)
● Diet rich in meat and seafood
● Genetics (mutation of urate transporter genes)
● Hyperglycaemia
● Obesity
The definitive diagnostic test for gout
identification of urate crystals in synovial fluid aspirated
from an affected joint. However, in practice this test is not
carried out often (only in 11% of cases)
According to the American College of Rheumatology,
presence of six or more of the following clinical features
indicates a diagnosis of gout
● More than one attack of acute arthritis
● Maximum inflammation developing within 24 hours
● Attack of monoarthritis
● Erythema over the affected joints
● Painful or swollen first metatarsophalangeal joint
● Unilateral attack on tarsal joint
● Tophus (suspected or proven)
● Hyperuricaemia
● Asymmetric swelling within a joint witnessed via
radiography
● Subcortical cysts without erosions visible on a
radiograph
● Joint fluid culture negative for organisms during the
acute attack
Janssens clinical prediction rule
It sets out seven criteria
and attributes a score for each criterion met. If a patient
scores <4 a diagnosis of gout is highly unlikely. If a score
of >8 is achieved then it is more than 80% likely that gout
is an accurate diagnosis. The criteria are outlined in Box 2.9
Patients who score 8 or more using the Janssens clinical
prediction rule should be started on empirical treatment
pending laboratory results (such as SUA level).
- Male 2
- Previous arthritis attack 2
-Onset <1 day 0.5 - Joint redness 1
- Involvement of first metatarsophalangeal
joint 2.5 - Hypertension or other cardiovascular disease 1.5
- Serum uric acid concentration >350µmol/L 3.5
The recommended dose for an acute attack of gout of colchine is and common side effects
500µg of colchicine two to four times a day.
Common side effects include abdominal cramps, nausea and vomiting. Rarely, bone marrow suppression, neuropathy and myopathy can also occur.
Colchicine is metabolised by
Colchicine is metabolised by the cytochrome P450 isoenzyme CYP3A4 and excreted by P-glycoprotein. Increased serum drug levels and toxicity can occur when colchicine is prescribed concomitantly with some medicines, including macrolides, ciclosporin and protease inhibitors. The absorption of vitamin B12 may be impaired by chronic administration of high doses of colchicine.
Common doses of intra-articular corticosteroids include
methylprednisolone acetate 80mg for large joints, such as a knee, and methylprednisolone acetate 40mg or triamcinolone acetonide 40mg for smaller joints, such as a wrist or elbow.
Oral corticosteroid regimens include
Prednisolone 30mg daily for one to three days, with subsequent dose tapering over one to two weeks. Corticosteroids may cause fewer adverse events than other acute treatments when used short term, particularly in the elderly.
The uricosuric medicines
probenecid and
sulfinpyrazone
are not used for patients with moderate or severe CKD because they require a GFR >50ml/min to be effective
However, benzbromarone can be used for patients with GFR 30–50ml/min
allopurinol and febuxostat inhibit the
metabolism of
of both azathioprine and 6-mercaptopurine.
Extreme caution is required when prescribing an XO
inhibitor to a patient stable on these medicines
Self-care
Advise the person to:
Rest and elevate the limb.
Avoid trauma to the affected joint.
Keep the joint exposed and in a cool environment.
Consider the use of an ice pack or bed-cage.
After an acute attack of gout has resolved, follow up the person after
4–6 weeks, and:
Check their Serum uric acid level.
Measure blood pressure and arrange additional blood testing for HbA1c, renal function, and lipid profile.
Identify and manage underlying conditions such as hypertension, diabetes, dyslipidaemia or renal impairment, and assess the person’s overall cardiovascular risk.
Provide advice on risk factors such as obesity, diet, excessive alcohol consumption, smoking and exercise - see Lifestyle advice section.
Advise that acute flares of gout should be treated as early as possible.
Consider providing an advance prescription of effective treatment for future attacks of gout.
Discuss the use of urate-lowering therapy (ULT).
Can urate-lowering treatment be reduced or stopped in chronic gout?
Once allopurinol or febuxostat is started, treatment is usually lifelong.
After some years of treatment, once serum uric acid target is reached and clinical ‘cure’ has been achieved (acute attacks have stopped and tophi have resolved), consider reducing the dose of ULT to maintain the serum uric acid level between 300-360 micromol/L.
Although in most people ULT will be required lifelong, consider stopping allopurinol or febuxostat only in people who have achieved a clinical ‘cure’, successfully addressed modifiable risk factors and had a normal serum uric acid level for many years.
Acute attack of gout treatment
- Treat as early as possible
- Patient education
- NSAID ( or coxib) plus PPI
or - Colchine 500ug bd-qds
or - Corticosteroid (ia, oral, im, iv)
- Consider adjunctive non-pharmacological treatment (topical ice, rest)
